The traditional image of interactive entertainment - games that reduce players' physical involvement to moving a joy stick - is obsolete. Games researchers and designers are already integrating complex movement into games. Location-based games involve body movements beyond figural space - that is, beyond the space of computer screens and small 3D objects. They focus on locomotion in vista space, typically a single room or sports field, or in environmental space, such as a neighborhood or city. Several location-based games have been designed for environmental space using localization technologies such as GPS. Some are adaptations of popular computer games, and others are rather straightforward chase games. A third type of game - what we call challenging location-based games - combines the intellectual and strategic appeal of classic board games with the real-time locomotion and physical involvement of location-based games. Furthermore, a straightforward approach to the spatial mapping of classic board games doesn't work. Instead, we developed the Geogames framework, which uses search techniques to identify a single temporal parameter for balancing sportive versus strategic elements